U.S. President-elect Donald Trump indicated a tougher U.S. approach to China by speaking to Taiwan's president last week, but how far he will push a risky test of wills to wring concessions from Beijing on issues from trade to North Korea is unclear.
The call between Trump and Tsai Ing-wen was the first by a U.S. president-elect or president with a Taiwanese leader since President Jimmy Carter switched diplomatic recognition to China from Taiwan in 1979.
It prompted a diplomatic protest from China which the outgoing Obama administration warned could undermine progress in relations with Beijing, which has been carefully built up over decades by both Republican and Democratic administrations.
Analysts say it could provoke military confrontation with China if pressed too far.
